BLOOMINGTON – Jim and Tomi Allison’s new Chevy Volt runs mostly on coal-powered electricity. But not for long.

When they install solar electric, also known as photovoltaic, panels behind their house, their car will be running on sunshine – mostly.

The car can travel 46 miles exclusively on its lithium ion battery, and after that, an on-board gasoline-powered generator kicks in to recharge the battery, extending the driving range to around 400 miles.

“There’s no range anxiety,” said Jim, an emeritus professor of psychology at Indiana University.

“This is a brilliant car,” he said. “GM has really wowed me with their engineering.”

They traded in a Prius and a Mazda MX5-Miata to buy the Volt, intending to simplify their lives by going from two cars to one.

He said the Volt is heavier than the Prius and feels more solid. He thinks it will handle winter driving conditions better. The Volt’s 1.4-liter engine has plenty of pickup and the car has lots of leg room and trunk space.

Jim agrees the Mazda sports car was more fun to drive, but otherwise, he is very pleased with his new car.

The couple has had the Volt for not quite four months and put around 3,000 miles on it. Since short trips use no gasoline at all, the car is getting 85 miles per gallon.

Tomi, who was mayor of Bloomington from 1983 to 1995, makes several round trips to nearby Nashville each week in the car completely on battery power.

“In theory, you could go forever without putting a drop of gas in the car,” Jim said.

He said he expects even higher mileage during the winter, since the couple will make fewer long-distance trips, and he forecasts a year-round average of 90 miles per gallon.

“They designed this car for everyday driving, and they hit the nail on the head,” he said.

Alex Jarvis, owner of Solar Systems of Indiana, is working with the Allisons as they plan their backyard power plant. They’ll soon install a 1-kilowatt system on the roof of a rear, second-floor bathroom, and then add three more units above a garden trellis in the back yard.

The 4-kilowatt system will produce and offset as much electricity as the Allisons use in their house – including recharging the car.

Jim said he looks forward to watching his electric meter run backward on bright, sunny days.

According to GM’s website, the manufacturer’s suggested retail price of a bare-bones Volt is $39,145. But a $7,500 tax credit softens that, and with their two trade-ins, the Allisons paid around $9,000 for their new car.

Jarvis said the payback period for their rooftop solar system will be about 16 years, but less if electricity prices climb.

“Believe me, the government is helping out on this,” Jim said, noting that not only will he get a hefty tax credit on the car, the federal government also offers a 30 percent tax credit on the PV system.

He said he had toyed with the idea of installing a PV system for quite a while.

“This car incentivized me to get serious about it,” he said.

He did some other cost calculations: When they had two cars, the couple spent about $1,528 a year on gasoline. But with one car, a Volt, he expects that to drop to $736. He would expect to see $249 in higher electric bills each year to charge the car, but after the solar panels are installed, his electric bill will become negligible.

But Jim points to other cost-savings: The couple is paying insurance, registration and maintenance for one car, not two. He says the Volt is a low-maintenance machine, requiring oil changes only every 7,500 miles.

And what is the uncollected dollar cost of the carbon emissions of gasoline-powered cars? When the Allisons take short trips in their Volt, their car has zero emissions.